Transfection using lasers

For successful delivery of foreign DNA into cells in vitro, the cell's architecture must remain intact while allowing a high degree of transfection. But current methods give sub-optimal transfection efficiencies. In 18 July Nature, Uday Tirlapur and Karsten König at theFriedrich Schiller University, Jena, Germany, show that a femtosecond pulse laser can efficiently transfect a variety of mammalian cells with DNA (Nature 2002, 418:290-291).

Tirlapur and König used a high-intensity near infrared, femtosecond-pulsed laser beam directed at Chinese hamster ovary and rat-kangaroo kidney epithelial (PtK2) cells. The laser made transient perforations in the cell membrane through which a plasmid DNA vector encoding enhanced green fluorescent protein (eGFP) could enter. Irrespective of cell type, the transfection rate achieved using this technique was invariably 100%.

"The ability to transfer foreign DNA safely and efficiently into specific cell types (including stem cells) - circumventing the need for mechanical, electrical or chemical means - will be an encouraging advance for a range of ventures, including targeted gene therapy and DNA vaccination," suggest the authors.